Plunger-elevator-retarding mechanism.



A. L. SGHULLER. PLUNGER ELBVATOR RETARDIN G MEGHANISM.

APPLIOTION FILED AUG. 24, 1.905. l

' Patented July 26 entre TTE PATENT UFFCE..

ALFRED L. SCHULLER, 0F CHICAGO, ILLINOXS, ASSIGNOR TO OTIS ELEVATOR COMPANY, OF JERSEY CI'lzlvY, NEW JERSEY, A CORPRATION 0F NEW JERSEY.

PLUNGER-ELEVATOR-RETARDING MECHANISM.

Specification of Letters Yatent. i Patented July 26, 1910.

`Application filed August 24, 1905. Serial No. 275,532.

To all whom it may concern.'

Be it; known that I, ALFRED L. SCHULLER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new andl useful Improvement in Plunger-ElevatorRetard ing Mechanism, of which the. following is a specification.

My invention relates to plunger elevators and has for its princi .al object the provi sion of simple and e cient means for retarding the motion of the car after the sup- .ply pressure is cut ott or reduced.

@ther objects of the invention will appear hereinaftcnithe novel combinations ot elements being pointed out in the claims hereto l appended.

Referring to the drawings, Figure' 1 represents a plunger elevator system with my invention applied thereto; Figs. 2 and'3' are detail views of the check valve at the lower end of the plunger; and Fig. l is a detail view in sectlon ot' the check valve 13 in the filling-in pipe 12.

1 designates the elevator car to the lower side of which is secured the plunger 2 and to the upper side of which is fastened the cable 3, this cable passing around the overhead sheave 4 to the countcrweight 5.

7 designates thc cylinder forreceiving the plunger 2. This cylinder is buried in the ground 9 and has a stuffing box 6 forthey plunger 2 and communicates at its'up-per end by means of a pipe 8 with the change valve l0, preferably a balanced three-wayA valve. This pipe is connected by the pipe 11 with the pressure tank 16 which in turn is connected with a suitable pump 18 by means o'l' a pipe 17.

The valve stem 28 has a rack 32 which meshes with a pinion 29 on the tlier sheave or shipper sheave 33. rope or shipper rope 19 passes around the flier sheave 33, through the ca-r 1 and around the overhead shcave 20. Also connected with the valve 1() is a discharge pipe 30 leading upwardly to the discharge tank 15 whichl is placed a little above the upper limit of travel of the elevator car. At the point 14 a suction pipe 31 is connected to the discharge pipe il() andlcads to the pump -18. A filling-in pipe l2 all'ords communication between the discharge pipe 3() and the cylinder supply pipe 8 but has a check n endless o eratine' valve 13 in it so that the water or other motive tluid can flow only in one direction, viz., from the discharge pipe 3() to the pipe 8.

As illustrated in Figs. 1 and 2, the pluner 2 is made hollow but has openings 23 1n its bottom 27. These 'openings may be of any desired size or 'number or arrangement. The* ressure is communicated through these opemngs to the iiuid in the plunger and acts at the bottom of the car to lift the same. A valve 22 is provided for the upper end ot plunger 2 which valve is operable from inside of the car to allow any air that may accumulate in the upper end of the plunger to escape. Such a valve in the car for the plunger is necessary as otherwise the car would tend to jump up and down While coming to rest on account of the elastic air cushion in the upper end of the plunger.

When the car is traveling upwardly and the rope 19 is actuated from the car to move the valve -10 to closed position the car has a tendency to run away from the motor fluid and then to fallback again with a thud. To prevent this water hammer, as it is called, the check valve 13 opens automatically and allows water to flow from the discharge pipe 30 'at the proper rate of speed to prevent the formation of any vacuum or to lill up any vacuum in the plunger or cylinder. In order to secure the necessary head to keep the plunger full of water at all times and particularly when the car is at the upper limit of its travel, the discharge tank must be placed adjacent such up er limit. This is for the reason that the -va ve26 hereinafter described may not entirely close the holes 23 in the bottom 27 of the plunger either when desired or at other times. For instance, if the valve26 leaks, a vacuum will form in the plunger at the bottom of the car as welll as at the bottom of the plunger, and the car after stopping in its upward travel will fall back onto the water in the plunger with a shock. A check valve in combination with the requisite head for the prevention of the formation of a vacuum in a plunger is disclosed in a patent to Crane, (361,575, November 13, 1900,' hy'- draulic elevator, y

It is ay well known fact that the etliciency of the plunger elevator machine is consider ably lessened, on high speed work particusupply is cut off reasonable limits, thus'admitting ofvacloser .Counterbalancing and increasing the '.eiiic'iency. In order to-aceomphsh thls. result,

I not onlyy make the plunger hollow and .permit the Water to enter the interior of the pl'ungerYa-nd have its head 27 provided Withhroles 23 and a check valve-26'.' Ithe holes are sufficiently re duced in size the check valve may be omit` ted.v The head 27 may be integral with the plunger 2, Welded thereto or otherwise tightly secured in place.- AQn the inside-of this head is a lug'orgprojeetion 2-tto Which is pivoted the check Valve 26. rlhis check valve is fitted on a finished metal seat, preti erably `of some non-corrosive metal and opens inwardly. rThe holes 23 are of such size, number and arrangement -that the iva- -ter may easily enter the interior of the plunger and properly transmit its pressure.

It is to be understood that'the head of Water inthe plunger is always maintained by the pressure backof it, but should this Y pressure beeome'lessthan that due to the be .illustrated v by head in the plunger the check valve will instantly lclose,'preventing its escape. Should any Water leaklout through the check valve 26 the plunger Willof course tend to settle but the head of .thexwater from the discharge-tank will prevent this so that at all times the plunger is filled with water.

The object oi the check valve 26 and the keeping of Athe plunger filled with Water may assuming an unbalanced car ascending light-and at approximately six hundred feet a minute. Let the'supply be eut oii at the speed at which the change valve vordinarily operates.l NVith-the ordi4 naryclosed plunger the resultwould be that kthe car would coast and the plungerA run away from the Water'and then fall back with coi'i'siderable shock. t Under the conditions noted above, however, the instantthe supply pressure is cut olf o r suiently, reduced, the

-headoi Water in the plunger would be unsupported and consequently7l the check valve Qwvould close to trap or lock .the'watcr in thehollow plunger and the total Weight in 4the plunger would act as a retarding force to stop the car. The'illing-in' pipe 1Q Which contains the cheek valve i3. would take care of thevacuum tending to forinwhen the rassure vact directly- -under the platform o4 the car, but I also close the bottom end Vof the plunger by va main supply is cut off and the valve 2G closes `the openings Q3, this vacuum tending to form under the head `27 inthis instance, but if the valve does lnot entirely close the 'holes 23 then also in the top portion of the plunger under the car. This lillingdn -pipe l2aand check valve 13 may be so'regulated that the Watervvould HOW throughthesame at such a speed as-to justfkeep pacewith the vacuum,I when the car aseends, care beingftaken that the Wa't'er through the filling-inpipe L'shall not produce-any pressure on the bottom of the plunger and thereby neutralize 'the retarding force dueto its unsupported 'Weight The loss of pressure at ythe bottom of the cary inside the plunger as the plunger is lifted is ,compensa-ted for by the increased counterweighting due to counterweight cable 3 run over to the-other'side of the overheadv sheave Il. The pump 18 Will Work from a suction pressure equal to the discharge head and deliver at a corresponding higher pressure to the pressure tank 16 Vwhich is-partly filled with air to equalize the vpressure in the plunger in a well-known manner.

If the discharge tank 15 is raised 4to any heightH the'pressureon the bottom of the plunger is raised .434 H X A, (the areaof i 'the plunger) and equilibriumis destroyed by this amount. To reestablish equilibrium either the counterweight must be` reduced this amount, or Weight be added-'to `the plunger to this amount," or ay combinationof both. No loss of power is occasioned by raising' .the discharge tank sinceA the c increased height is utilized as suction head on the pump. v creased Weight is placed in theplunger it makesvno diiference what its material may be.' New, While this addition 'of Weight in the plunger, (or equivalentreduction of the balance'weighu) vis compensatedby 'the ele- It 'is evident that if such in- I vation of the discharge tank, and therefore y the statie conditions are unchanged, the dynamic conditions are changed, for,whejn an up motion stop is made, and the change valve is closed suflic'iently to reduce the pressure.

in 4the cylinder by an amount. equal to the elevationfof the discharge tank, the added Weight is at once unbalanced and acts to retard the moving masses; `Hene itis seen that elevati-ng' Vthe discharge tank aids in stopping While leaving static conditions unl changedandi the increased head is used as suction head onthe pump, increased economy is attained, but that 'thenature of the Weight used to odset. the elevation of the tank is in filling the pluiug'er with water that is gained by Weighting ,it to an equivalent.

amount.

` The .placing of the Water in ther-interior of.y the plunger has the further advantagefot puttingthe plunger', in most cases, in tension instead ot' incompression. lf the plunger lis immaterial, and vthere isthe same advantage I and the only compression on the bottom area of the metal itself.

is hollow and empty and the end capped the walls of the plunger must sustain the entire Water pressure on the bottom of the plunger. But if the end is open and the plunger full of water to the top, the pressure is conveyed through the water to the bottom of' the car, the metal of the plunger is that due "to the water pressure on Taking the ordinary six and one-half inch lunger, say one-quarter inch thick, the total) area is v about thirty-three square inches, and the annular area of the metal but about five square inches. Therefore when the plunger is filled with water the compression on the metal is but five thirty-thirds of what it is in the ordinary case. Thisundoubtedly is a gain, and the plunger is still further stiff'- ened by thc tension due to the internal radial pressure and to the weight of the water Having thus described my invention and without limiting myself to the precise oon struction of details or arrangement of parts, what I claim and desire to have protected by Letters Patent of the United States is:

1. The combination with a car, of a hollow plunger, means permitting the plunger to be filled with the motor fluid, and means for locking said fluid in the said hollow plunger at all times.

2. The combination with acar, of a hollow plunger arranged to 'be filled with the motor fluid, means for controlling the flow' of the motor fluid, and means for trapping the fluid in said plunger under all conditions.

3. The combination with a car, of a hollow plunger, means for controlling the fluid pressure tov move said plunger andcar, and vmeans for confining the fluid in said plunger and maintaining the latter filled irrespective of its osition when the supply pressure is reduce or entirely cut o'.

4. The combination with a car, of a hol: low plunger arranged to be filled'- with the motor fluid, means for-controlling the flow of the motor fluid tolsaid plunger, means permitting the pressure to be communicated to the Huid withiiidl'ieplunger. and means for preventing the flowgoj -lliiidfroui said plunger. at all times. f

5. The combination with a. car, of a hollow plunger, means permitting said plunger to be filled with fluid, means forcontrolling the transmission of pressure to the fluid withinithe plunger, and means for preventing the fluid from drainiii from said plunger when the latter is at its lower limit of travel. v

(i. The combination of-a car, a hollow plunger movable therewitiif," means permit ting the plunger to he filled with fluid, means for controlling thc pressure connnunicattal 'to the interior of said plunger, and means operable during the upward travel of the car and plunger andvinde 'endently of the position of the plunger ir automatically trapping or confining the fluid in the plunger upon reducing the supply pressure or upon entirely cutting off the same.

7 The combination with a car, of a hollow plunger secured thereto a cylinder for receiving said plunger, valve mechanism, means for operating said valve mechanism to control the fluid pressure, and means for confining the fluid within said plunger during its entire travel in either direction. K

8. The combination with a car, of a hollow plunger fixed thereto, a cylinder for receiving said plunger, valve mechanism for controlling the application of fluid pressure at the upper end of said plunger, and means for trapping the fluid in the Vplunger to retard the motion of the car and lun er when the supply pressure is reduce an to prevent said fluid from draining from lsaid plunger in an other position thereof. e Y

9. The com ination with a'car, of a. hollow plunger, means for controlling the application of fluid pressure at the upper end of the plunger-near the bottom of thecar, and means for checking the flow of fluid from said plunger when the supply pressure is reduced and the car is traveling upwardly and when the plunger is in any other position.

10. The combination with a car, of a hollow plunger for said car, means for controlling the transmission of pressure to the fluid within said plunger, and a. check valve for said plunger to trap the fluid wit-hin the plunger when the sup ly pressure `is rcduced and to hold the uid in said plunger at all other ositins of the latter.

11. A ho low plunger for an elevator closed at its upper end, and having a bottom at4 its lower end provided with apertures therethrough, and a check valve wholly within the plunger, opening inwardly and resting on Said apertures. g

12. A hollow plunger for an elevator,

closed at its u er end and havi-n a bottomv at-ts lower en provided with two or more apertures therethrough and a check valve wholly within the plunger operated by dif# ference of fluid pressure within and without the plunger to close or open said apertures.

13. Thecombination with a car, of a h0l low plunger therefor arranged to be filled with the motor-fluid, means for controlling the movements of the car and plunger, and means for confining the fluid inthe plunger to retard the motionof the car when the supply pressure is reduced and to trap the fluid within the plunger when the car is atthe lower limit. of its travel.

14. The combination with a car, of a hollow plunger therefor, a cylinder for saidy plunger, means for controlling the motor- `and a valve lor aiuoxnalically cl Afluid pressure :,ujiplied to iluid to and trom said cylinder, and a check valve at the ybottom of said plunger and Wholly Within the latter.

l5. The combination with a car, of a holloiv plunger with one or more openings therein, means for controlling the transmission'. oi' pressure to fluid within the plungeil through said opening or openings, and

` means dependent entirely upon dil'lierence of fluid pressurev for closing` said opening or openings at any position of the car.

16. The combination with a car, of a hollow plunger connected thereto and having `its lower end perforated, means for controlling the fluid pressure to the interior and exterior ol said plunger, andvmeans `for maintaining'said phinger illed "with Alluid during its "upward travel irrespective ofits position. f

l?. rlhe combination with a car, of a hol low plunger provided with pertorations, means for controlling the supply oit fluid Au'essrn'e, to said plunger, and a valve for automatically closing said perforations upon the supply pressure heing reduced. and maintaining said pert'orations closed for any stationary position of the car.

1 8. "'.lhe conidiination with a car, ot' a hollow plunger provided with perforatiousat its lower end, means :tor controlling the transmissionof 'fluid pressure 'to fluid, withf' through su id` ,perilla-ations7 said ijierforations when the supply pressure is .cut oli and the car is traveling upwardly in said plun and mai 'taininv said ner'torations closed tor anystationnry position oli the car.

l). jflhe combination vvi'th a car, 'of a holvlow` plunger vprovided with one or more openings, n'leans tor closing said opening or openings, fluid pressure supplying means .tousaid plunger, means for controlling the said plunger, and a discharge tank adjacent the upper limit of the travel of the cai'.

QG. The combination with a car and a hollow plunger, oi means 'for controlling i transmission et liuir'l pressure to the interior r pipe.v

o't` said plunger, fluid pressure supplyingf ineans,.a discharge 'tank adjacent the upper limit of travel of said car, and connections between said tank and said controlling means, said connections comprising a check valve.

Q1; The combination with a car and va hollow plunger, 'of a cylinder .torsaid plunger, means comprising a change valve llor controlling transmission of fluid pre-- sure tothe interior of said" plunger, fluid' pre'ssu13e-supplying means, a discharge tank, a pipe connecting said controlling valve to said discharge tank, an additional pipe con- `meeting said last-named pipe vvithfthecvlinder, v'and a check valve inV said additional 22. The combination with a carl', of a hollow plunger secured at its upper end to the car and provided With a bottom having apertures therethrough, means for control* ling" the supply of liuid tothe plunger, and

a discharge tank located at aboutthe upper limit of travel of the Garland having connection with the plunger.

lovv plunger secured at its upper end to the car and provided With a bottom having one or more apertures therethrough, means for controlling thefsupply of lluid to the car and having apertures in yits bottom, an inwardly opening valve Vtor vclosing said apertures, fluid pressure-controlling valve 'tank at or near the upper limit of travel of the car, discharge tank to said controlling means, a branch pipe around said controlling valve mechanism, and a check valve in said branch rire 2G; The combination with a car, of a hollovv plunger secured at its upper end tothe car and havingits bottoni providedwith apertures, a check valve yfor automatically plunger, a change valve for cont-rolling the lloiv of fluid to and from said cylinder, a discharge tank adjacent the upper limitof travel oit' the car, a discharge pipe connecta bypass pipe from the discharge pipe and passing` around said change'valve to 'said cylinder, and -a check valve in said lay-pass pipe and'opening toward said cylinder.

27. The combination with a car, of aholloiv plunger provided with openings in its bottom, a valve opening inwardly for`cl0sing said openings, a cylinder for the plunger, fluid pressure-supplying means comprising a` pump and pressure tank for transmitting pressure through the liuid in the lplunger to the top of the plunger at? or near the bottom of the car, controlling valve mechanism;V between the cylinder and said pressure limit of travel. of said car, a` discharge pipe connecting the'exhaust port of saidvalve serv .23; The combination with a car, of azhol-v low plunger secured at itsl upper end to the closing said apertures, a cylinder for Isaid plunger, a valve for said aperture or `apen@ 241:. The combination With a car, of a. hol-4 mechanism for said plunger, a discharge i discharge pipe connecting said ing said discharge tank to said change valve,...

tank, a discharge tank adjacent the upper,`

mechanism to said discharge tank, e sucname t0 thisspeeification in the presence of tion pipe between said discharge pipe and two subscribing witnesses. y

said pump a filling-in pipe between said discharge pipe and the lun er cy1nder,and ALFRED L SCHULLER K a cheek valve in Sai fil ing-m-pipe and 4VVitnesseS: opening toward the cylinder. Gr. M. MCCAULL,

In testimony whereof, I have signed my "Wim H. DUNN. 

